def npLogPDFDirichlet(mu, params):
mu = np.array(mu)
params = np.array(params)
assert (len(mu) == len(params))
assert (bd.ispv(mu))
logPstr = np.sum((params - 1) * np.log(mu))
logZ = np.sum(log(vgamma(params))) - logGamma(np.sum(params))
return logPstr - logZ
def append(self, theta):
assert(bd.ispv(theta))
if not(self.__pointer in range(self.__record.shape[1])):
self.__record = np.concatenate([self.__record, np.zeros((self.__record.shape[0], self.__allocUnit))], axis=1)
self.__counter= np.concatenate([self.__counter,np.zeros(self.__allocUnit)])
self.__record[:,self.__pointer] = theta
self.__counter[self.__pointer] = 1.0
self.__pointer += 1
def pdf(self, mu):
"""Probability Density Function"""
mu = np.array(mu)
assert(len(mu)==self.dim())
assert(bd.ispv(mu))
pstr = np.product(mu**(self.__params-1))
Z = np.product(vgamma(self.__params))/math.gamma(np.sum(self.__params))
return pstr/Z
def npLogPDFDirichlet(mu, params):
mu = np.array(mu)
params = np.array(params)
assert(len(mu)==len(params))
assert(bd.ispv(mu))
logPstr = np.sum((params-1)*np.log(mu))
logZ = np.sum(log(vgamma(params))) - logGamma(np.sum(params))
return logPstr - logZ
def pdf(self, mu):
"""Probability Density Function"""
mu = np.array(mu)
assert (len(mu) == self.dim())
assert (bd.ispv(mu))
pstr = np.product(mu**(self.__params - 1))
Z = np.product(vgamma(self.__params)) / math.gamma(
np.sum(self.__params))
return pstr / Z
def posterior(self, sample):
"""
computes the posterior of DP
sample: index of the observed word for topic learning
"""
posterior=np.zeros(self.noClusters()+1)
posterior[:-1] = self.__lfs.compute(sample) * self.__lfs.counter()
posterior[-1] = self.alpha * self.baseDist.Zpost(sample)
posterior = posterior/np.sum(posterior)
assert(bd.ispv(posterior))
return posterior
def append(self, theta):
assert (bd.ispv(theta))
if not (self.__pointer in range(self.__record.shape[1])):
self.__record = np.concatenate([
self.__record,
np.zeros((self.__record.shape[0], self.__allocUnit))
],
axis=1)
self.__counter = np.concatenate(
[self.__counter,
np.zeros(self.__allocUnit)])
self.__record[:, self.__pointer] = theta
self.__counter[self.__pointer] = 1.0
self.__pointer += 1
